(PECL fann >= 1.0.0)
fann_subset_train_data — Returns an copy of a subset of the train data
   Returns an copy of a subset of the train data resource, starting at position
   pos and length elements forward.
  
   The fann_subset_train_data(train_data, 0, fann_length_train_data(train_data)) do the same as
   fann_duplicate_train_data()
  
dataNeural network training data resource.
posStarting position.
lengthThe number of copied elements.